WO2017042740A1

WO2017042740A1 - Hydraulic centrifugal axial horizontal turbine

Info

Publication number: WO2017042740A1
Application number: PCT/IB2016/055398
Authority: WO
Inventors: Marino PIASENTA'; Gabriele BIGNOTTI
Original assignee: CONTINI, Paola; Laboratorio D'innovazione S.R.L.S.; Brennero Innovazioni Tecnologiche S.R.L.
Priority date: 2015-09-09
Filing date: 2016-09-09
Publication date: 2017-03-16
Also published as: ITUB20153508A1

Abstract

The horizontal axial centrifugal hydraulic turbine (1) comprises: a central section (2) comprising a plurality of central blades (3) with a substantially flat shape, arranged radially; a rib (4), arranged perpendicular to the flow of water in the proximity of said central section (2), having a plurality of drain drills (5) and adapted to define an area of turbulence and pressure increase; a plurality of lateral blades (6) having a radiating bend (7) which ends at the outlet in the proximity of respective lateral crowns (8), the shape of which is adapted to convey the flow of water in a perpendicular direction (O) and at outlet through respective lateral crowns (8). The turbine (1) utilizes the kinetic energy of the flowing water (river, channel, sea currents or other type of flow) to produce electric current or also simply kinetic or mechanical energy with transfer. From the mechanical point of view it has the peculiar characteristic to recover kinetic and mechanical energy over the entire surface, both in the direction of the current flow of water, both in the opposite direction, thanks to its particular geometry.

Description

HYDRAULIC CENTRIFUGAL AXIAL HORIZONTAL TURBINE

Technical Field

The present invention relates to a horizontal axial centrifugal hydraulic turbine. Background Art

The state of the art as far as the turbines on the market are concerned consists to a large extent in the use of building works with "falls", in such a way and so as to obtain the maximum working thrust on the few blades which are invested by the fluid.

Pelton, Francis and Kaplan are the main hydroelectric turbines and with respect to these, technicians try to achieve the maximum possible speed using falls and acting on a relatively small portion of the turbine, inasmuch as all the rest is in a neutral or even disadvantageous position with respect to rotation.

The problem of the neutral or even negative zone has also been addressed by vertical-axis turbines, with nevertheless similar problems. The Cross Flow Turbine and the Banky Ossberger Turbine are horizontal, but not centrifugal turbines, and these too have an operating mode only slightly dissimilar to those mentioned above.

All types of existing turbines, to achieve good results, must be based on falls, dams or steep gradients, because they have to directly exploit the impact of the water on the part which exercises the greatest rotation leverage (torque ratio).

Consequently, they must necessarily be very sturdy and heavy, and this reduces their range of use and operating capacity. The entire hydroelectric industry is characterized as dependent on major building works.

Description of the Invention

The main aim of the present invention is to provide a horizontal axial centrifugal hydraulic turbine for the production of hydroelectric energy or for the production and the remote use of mechanical energy.

With the hydraulic turbine according to the invention the problem is solved and all types of flowing water become available with very high efficiency, without the need for building works.

Furthermore these waters, until now not exploitable for the production of electricity in terms of cost-effectiveness, can also be exploited in series thanks to this new type of turbine.

The turbine according to the invention allows processing the water element without building works with environmental impact and advantageously exploiting the physical characteristics of the water element in its natural movement.

The turbine is thus invested without violence and on the entire surface of the blades.

With the weights distributed evenly over the entire working surface of the blades, the weight per square millimeters will consequently be much lower. Another object of the present invention is to lighten all the parts of the turbine, thus allowing the use of ultra lightweight materials.

Brief Description of the Drawings

Other characteristics and advantages of the present invention will become better evident from the description of a preferred, but not exclusive, embodiment of a horizontal axial centrifugal hydraulic turbine, illustrated by way of an indicative, but non-limiting, example in the accompanying drawings, wherein: Figure 1 is an axonometric view of the centrifugal hydraulic turbine according to the invention;

Figure 2 is a detailed view of the turbine of Figure 1 ;

Figure 3 is an axonometric view of the conveyor element of the turbine according to the invention;

Figure 4 is a front view of the flower- shaped rib of the turbine according to the invention;

Figure 5 is an axonometric view of a lateral blade of the turbine according to the invention;

Figure 6 is an axonometric view of a central blade of the turbine according to the invention;

Figure 7 is a front view of a lateral crown of the turbine according to the invention.

Embodiments of the Invention

With particular reference to such figures, reference number 1 globally indicates a horizontal axial centrifugal hydraulic turbine. According to the invention, the turbine 1 comprises a central section 2 (Figure 2) comprising a plurality of central blades 3 with a substantially flat shape (Figure 6), arranged radially.

Furthermore, the turbine 1 comprises a rib 4 (Figure 4), arranged perpendicular to the flow of water in the proximity of the central section 2, and having a plurality of drain drills 5 and adapted to define an area of turbulence and pressure increase (Figure 2 - portion comprised between the arrows I and Ii). In particular, the drain drill 5 of the rib 4 substantially defines the shape of a flower.

Again, the turbine 1 comprises a plurality of lateral blades 6 (Figure 5) having a radiating bend 7 which ends at the outlet in the proximity of respective lateral crowns 8 (Figure 7), the shape of which is adapted to convey the flow of water in a perpendicular direction (represented in Figure 2 with the arrow I), and at outlet through respective lateral crowns 8 (represented in Figure 2 with the arrow O).

Advantageously, the turbine 1 is total immersion for flowing water.

The turbine 1 comprises at least one conveyor element 9 adapted to interact with the lateral blades 6 and the central blades 3, the rib 4 and the lateral crowns 8. The lateral crowns 8 comprise a central hole 8 a and a plurality of drain holes 8b. In particular, the conveyor element 9 comprises a plurality of dividing walls 9o, 9L (Figure 3).

Preferably, at least one of the above mentioned dividing walls 9o, 9L is substantially horizontal.

At the same time, at least two of the dividing walls 9o, 9L are lateral.

The dividing walls 9o, 9L are adapted to define at least one vacuum area X, Y, Z, W.

In the present case, such dividing walls 9o, 9L are associated with at least one floating support table, not shown in the illustrations.

The floating table is placed over the entire conveyor element 9 (not essential and useful only for certain circumstances and for this not present in Figure 1), bears the full weight and is able to make the instrument follow the change in height of the river, or canal, or water course, or sea level. Above the floating table will be positioned the permanent magnet alternator, the dynamo or the mechanical conversion or anything else useful for the energy conversion and which falls within the prior art.

Figure 1 schematically shows the characteristics of originality in the flow of water.

In particular, the letter B represents the forced inlet of water from the conveyor element 9 on the blades 3, 6 of the centrifugal turbine 1 with predetermined direction and angle.

The blades 3, 6 (Figure 2) invested by the flow create a Venturi effect in the direction of the center of the turbine 1, the water finds the lateral escape routes in the drain drills 5 of the flower- shaped rib 4 (Figure 4). The water now finds itself on the lateral sections 10 (Figure 2). The blades 6 which the water encounters have a shape guiding towards the outside (Figure 5). In the lateral crowns 8 (Figure 7) the drills further increase which direct the flow of water perpendicular towards the outside.

Similarly, the letter C represents the perpendicular outlet flow, visible in detail in Figure 2 and indicated with the arrow O.

At the same time, the letter D represents the vacuum area caused by the conveyor element 9 which sucks up the centrifugal flow of the turbine, facilitating it.

Finally, the letter E represents a counter-current flow resulting from the contemporaneous activity of the conveyor element 9, which mechanically causes the vacuum, and from the water barrier created by the sturdy centrifugal and perpendicular flow leaving the turbine 1. This water flow coming from downstream also contributes to the Venturi effect created in the center of the turbine 1 which then translates into the increase in the centrifugal flow.

In figure 2, the arrows O represent the centrifugal outlets, perpendicular and facilitated by the vacuum caused by the conveyor element 9, which in turn form a vacuum which facilitates the recall of the water against the normal flow.

The normal flow, represented schematically by the arrows I, pushes the blades 3, 6 of the turbine 1 which are invested in the desired direction and for the entire encountered surface. The normal flow of water I, investing the blades 3, 6 of the turbine 1 from upstream to downstream, triggers the rotary movement on the shaft 11 (Figure 2), mounted in turn on ball bearings 12 which facilitate the rotation thereof.

Advantageously, the inlet between the blades 3, 6 of the turbine 1 is two thirds larger than the outlet space between the two blades 3, 6. This gives rise to the Venturi effect in the direction of the flow up to the center of the turbine itself, here the flow is given the only possibility of perpendicular outlet (Figure 2 - arrows O) thanks to the drain drills 5 of the ribs 4 (Figure 4) and of the lateral crowns 8 (Figure 7) and the flow is channeled outwards, at a speed three times higher than the inlet speed into the turbine 1. The typical and unique feature resulting from the exploitation of the Venturi effect and of the centrifugal effect channeled laterally is to create a barrier or blade of water at very high speed which goes to hinder, outside the turbine 1, the normal flow of running water. Downstream of this barrier, consisting of the element itself, a natural vacuum is created that recalls the water itself at high speed, to invest the blades 3, 6 downstream, schematically shown in Figure 2 by the arrows Ii, in a way useful to the motion of the turbine 1. This way, the same motion is also generated countercurrent at the inlet to the turbine 1 coming from upstream. Consequently, water inlet is also achieved from downstream to upstream with the thrust on the blades 3, 6 that generates the rotary motion and, with symmetric inlet and the same outlet, in the above proportions, it generates the same Venturi effect towards the center of the turbine 1. This flow (Figure 2 - arrow Ii) generates with the same lateral and centrifugal outlet (Figure 2 - arrow O), but starting from downstream and towards upstream.

Now the blades 3, 6 are invested generating the rotary motion over the entire surface of the whole turbine 1 , thus increasing the overall capacity of the turbine to realize the rotary motion and, at the same time, uniformly distributing both the weights and the pressures on the entire device.

The arrows Ii, which indicate the motion, represent the counter-flow (Figure 2 - arrow Ii) which is the overall result obtained by the simultaneous activity of the conveyor element 9 (Figure 3) and of the geometric design of the turbine itself (Figure 2). It is the movement of the water itself which creates a barrier which causes the downstream vacuum and favors the counter-current activity of the turbine itself.

The turbine 1 according to the invention is original and innovative precisely because of this different use of the current flows, which results in the weight of the water used for the thrust being perfectly distributed over the entire surface of the turbine 1 , instead of only on one or some parts of it.

The consequence is that the mechanical stress of the blades 3, 6 is so well distributed that it is possible to use much less material and make a much lighter turbine 1.

In the version with a blade of 280 mm diameter and 450 mm total length, the turbine 1 has a weight of less than 3 kg, including the shaft 11 (Figure 2) and ball bearings 12 (Figure 2).

An original part of the invention is the geometry of the blades 3, 6 (Figures 5 and 6) and of the conveyor element 9 (Figure 3) adapted to the purpose and in the adjustable version, adapted to any speed of the flow.

In this regard, Figure 3 shows the profile of the conveyor element 9.

Thanks to the special profile of the conveyor element 9, the current is conveyed against the blades 3, 6 and at the same time, the vacuum areas are created, represented by the letter Y, which recall the water in new counter-current flows (Figure 2 - arrow Ii).

The inclinations of the dividing walls 9o, 9L are variable and adjustable favoring the specific speed of the water on the installation site.

The turbine 1 according to the invention is based on the knowledge and the precise use of the water element, as can be seen in the drawing of the conveyor element 9 (Figure 3).

This particular profile of the conveyor element 9 is crucial not only to determine the flow of the hydraulic current on the blades 3, 6, according to the desired inclination, but facilitates the vacuums which recall the counter flow on the rear blades 3, 6.

The horizontal dividing wall 9o is inclined downwards by 30° to 60° in relation to the different opportunities and models. The dividing wall 9o goes to take a greater mass of water and conveys it at high speed, with the desired inclination, to the turbine 1. Behind it (Figure 3 - letter X), it creates a vacuum exactly equal to the mass it is conveying and therefore recalls, against the normal flow, an equal amount of water, less the actual amount coming out of the funnel.

The funnel is the result of the conveyance determined by the dividing walls 9o, 9L shown in Figure 3.

This dividing wall 9o of the conveyor element 9 is also used as a mechanical braking device. Braking is adjusted by means of tension springs which, in the event of excessive flow, allow it to lift and to invest the turbine 1 over the entire surface (including that of the counter-flow) and thus slow down the rotation thereof.

The two lateral dividing walls 9L are horizontally inclined by 15° to 45°, with their opening they take a very large mass of water conveying it at high speed into the turbine 1. These two dividing walls 9o, 9L also create behind them a vacuum (Figure 3 - indicated with letter Y) equal to the mass that they are moving less the actual outlet of the funnel. These dividing walls 9o, 9L can also be used as a braking device. In detail, by using a pressure spring applied to the outer compensation shoulder 14, if the water flow were to increase its thrust and its speed excessively, the lateral dividing walls 9L will open and will convey part of the water onto the centrifugal outlet (Figure 2 - arrows O) of the turbine 1 , preventing the operation of the turbine itself, which will therefore slow down its number of revolutions without undergoing mechanical stress.

The outer shoulders 14, or compensation shoulders, are not perpendicular, but inclined outwards by 8° to 15°, this increases the general vacuum downstream of the instrument (Figure 3 - letter Y) and recalls here a greater quantity of water, thereby offsetting the above losses. The actions of the outer shoulders 14 are two: one, by widening outwards, creates an internal counter-flow, the other consists in the fact that by accommodating the centrifugal outlet of the turbine 1 in a larger space, an aid is given to the veil of water which it itself forms in favor of the counter- flow.

The letter X represents the upper horizontal vacuum which determines the counter-current turbine rotary motion.

At the same time, the letter Z represents the flow of water deflected by up to 30° towards the outside of the turbine 1 which facilitates and increases the counter- flow downstream.

Similarly, the letters Y represent the opening due to the lateral inclination towards the outside which goes to offset mechanically the losses caused by the exploitation of the direct flow of the current of the water flow; this solution leads to the equalization of the activity of the turbine 1 in the two directions, in favor of the current or counter-current.

The Y area is an area with mechanical-vacuum produced by the dividing walls 9o, 9L of the conveyor element 9 (Figure 3 - 9o, 9L, 14, W), but fluid- dynamically it is occupied by the outflow from the turbine 1.

By increasing or decreasing the angle of the two outer shoulders 14 (Figure 3), in consideration of the variable speed of the current flow, a vacuum area is obtained which is larger than necessary and this way the various losses are offset of the counter-current flow making them equal to the direct flow.

The outlet perpendicular to the flow of water (Figure 2 - arrow O) is therefore facilitated by the increased inclination of these same shoulders and in turn contributes to the original movement of rotation.

All the other turbines normally to be found on the market violently receive a high-speed flow on one part of the blades, i.e. those invested by the flow, and often also by a fall of water, and are therefore subject to having to support a very high thrust in kg per mm². This determines the choice of materials, their thickness, to obtain the required strength and therefore their weight will be the direct consequence of these requirements.

The turbines normally available on the market, therefore, are very heavy and require hydraulic and building works.

The turbine according to the invention is different and original in its shape too.

It is completely immersed in the element, and therefore in a uniform pressure status, and receives its circular motion with continuity over the whole surface.

The blades 3, 6 convey and deflect the flow in a perpendicular direction thanks to the shape and thanks to the vacuums, and consequently they suffer very little stress from a mechanical point of view.

For this reason the mechanical parts that make up the turbine according to the invention can be considerably lightened and, although with the peculiar design, which is intended for a rotary motion, they recall the technologies and techniques used in the aerospace industry more than the classic water or hydroelectric ones.

The rib 4, shown in detail in Figure 4, is an integral and determinant part of the present invention.

This very particular rib 4 is the one that supports the entire weight of all the blades 3, 6 and thanks to its structure, all superfluous weights being offloaded and lightened by the drain drills 5, it lightens the weight of the entire turbine and at the same time has well over the mechanical seal required to manage mechanical fatigue over the years.

This rib 4 can have a thickness of less than 1 mm and a very high mechanical seal at the critical point of rupture despite its lightness and delicate appearance.

In particular, the flower- shaped rib 4 is intended to bear the weight of the blades 3, 6 which, after receiving the water thrust, generate the rotary motion. These are immersed in the water and must discharge towards the outside the mass of water which, compressed into the funnel formed by the blades themselves, has increased its speed according to the Venturi effect diagram.

The features of the flower- shaped rib 4, in addition to the extraordinary mechanical seal with respect to weight, are the following:

1. the 1 mm slots where are inserted the fins 15, 16 (Figures 5 and 6) of the blades 3, 6, which will be retained by bending;

2. the drains and drain drills 5 of the flower-shaped rib 4 which convey in a suitable way the centrifugal flow from the central blades 3 (Figure 2) towards the two sets of lateral blades 6 (Figure 2) and, from here, through the lateral crowns 8 (Figure 7), the water will come out.

The flower- shaped rib 4 is located on the central section 2 and supports the non- directional blades. From the central section 2 (Figure 2) the water flows out due to the centrifugal pressure.

The flower-shaped rib 4 besides its function of supporting the entire weight of the turbine 1 also plays an active role in conveying the flows.

The flower-shaped rib 4 also has an extreme safety function in case of accident: its critical breaking point is at the center near the shaft 11 (Figure 2). In case of breakage, the entire turbine 1 will therefore fit itself onto the shaft itself without being able to release parts outside.

From the structural point of view, the blades differ according to their position on the shaft 11.

The lateral blade 6, with its characteristic shape, on the flat part receives the direct flow and, from the center of the turbine 1, also receives the mass of water coming out of the central section 2 (Figure 2) through the drain drills 5 of the flower- shaped rib 4 (Figure 4). The shape of the radiating bend on the outer side of the blade 6 starts the screwing motion of the water from the center towards the outside further facilitating the centrifugal movement and the perpendicular outlet of the flow (Figure 2 - A).

The central blade 3 presses towards the center of the turbine 1 and the centrifugal activity occurs by pressure and vacuum.

The central blade 3 conveys the flow to the center and laterally towards the outside by pressure, as in the most classic of movements of the centrifugal turbines.

The turbine 1 according to the invention can be made of any kind of material - metal, plastics, wood or others - but the use is always to be preferred of environmentally friendly materials or materials which can be totally recycled for the same use: for example, totally of Aluminum or, for specific applications, Titanium as in the case of brackish water.

The two lateral crowns 8 at the center are opened by means of a large central hole 8a and are drained with other drain holes 8b at the tangential outlets of the lateral blades 6.

They are very lightweight and supported by the blades themselves inasmuch as they undergo very little mechanical pressure.

Shape and lightness allow the turbine 1 according to the invention to rotate and produce energy in total immersion in a water course, exploiting in more or less the same way the flow of the current and at the same time and totally the counter-current flow.

For this reason the turbine 1 according to the invention also has the characteristic of working with a low flow of water and is therefore also suitable for the exploitation of the kinetic energy of tides and sea currents.

The turbine 1 according to the invention has no negative environmental impact, produces kinetic, mechanical or electrical energy, and immediately outside its narrow area of activity, the water will resume normal flow, making its installation unlimited on water courses, canals or in the presence of sea tides, including of slight entity.

It has in practice been ascertained that the described invention achieves the proposed objects.

In particular, the fact is underlined that the particular solution of providing a significantly lighter turbine compared to the turbines of known type together with the fact that its use is spread over the entire surface, has the following consequences:

• the cutting of production costs;

· the increase in the number of rpm as a direct result of the light weight;

• the increase in the thrust pressure in the pressure/speed ratio due to the operating surfaces which have now become all and not only some or a part thereof;

• the original counter-current movement is determined by the geometric shape of the turbine: the lightening of weight is essential to increase both its performance and its simple rotation capacity;

• because of the achieved lightness, the turbine according to the invention is also operative even with speeds below 0.2 meters per second.

To this is added the fact that the turbine according to the invention is characterized by the fact that the lateral centrifugal outlets create a blade of water which constitutes an obstacle to flow, thus recalling the water into the vacuum area which is now located downstream of the turbine itself.

Claims

1) A horizontal axial centrifugal hydraulic turbine (1), characterized by the fact that it comprises:

a central section (2) comprising a plurality of central blades (3) with a substantially flat shape, arranged radially;

a rib (4), arranged perpendicular to the flow of water in the proximity of said central section (2), having a plurality of drain drills (5) and adapted to define an area of turbulence and pressure increase;

a plurality of lateral blades (6) having a radiating bend (7) which ends at the outlet in the proximity of respective lateral crowns (8), the shape of which is adapted to convey the flow of water in a perpendicular direction (O) and at outlet through respective lateral crowns (8).

2) The turbine (1) according to claim 1, characterized by the fact that the drain drills (5) of said rib (4) substantially define the shape of a flower.

3) The turbine (1) according to claim 1, characterized by the fact that it is total immersion for flowing water.

4) The turbine (1) according to one or more of the preceding claims, characterized by the fact that it comprises at least one conveyor element (9) adapted to interact with said lateral blades (6) and said central blades (3), said rib (4) and said lateral crowns (8).

5) The turbine (1) according to one or more of the preceding claims, characterized by the fact that said conveyor element (9) comprises a plurality of dividing walls (9o, 9L).

6) The turbine (1) according to claim 4, characterized by the fact that at least one of said dividing walls (9o, 9L) is substantially horizontal.

7) The turbine (1) according to claim 4, characterized by the fact that at least two of said dividing walls (9o, 9L) are lateral.

8) The turbine (1) according to one or more of the preceding claims, characterized by the fact that said dividing walls (9o, 9L) are adapted to define at least one vacuum area (X, Y, Z, W).

9) The turbine (1) according to one or more of the preceding claims, characterized by the fact that said dividing walls (9o, 9L) are associated with at least one floating support table.

10) The turbine (1) according to one or more of the preceding claims, characterized by the fact that said lateral crowns (8) comprise a central hole (8a) and a plurality of drain holes (8b).